It's another conspiracy novel with more twists and turns than an Alpine road from chemist-turned-author Alan Calder.

In The Da Vinci Code, Dan Brown fictionally speculates that the Holy Grail lies buried in the crypt of Rosslyn Chapel, near Edinburgh.

But in his second online thriller The Glorious Twelfth, Calder twists Brown’s plot to suggest the holy relic is buried elsewhere in Scotland.

Alan, who lives in Meltham, suggests that the Sinclair family, who built Rosslyn Chapel, had a series of fortresses on the Caithness Coast, northern Scotland, which would have provided a much better hiding place for the Holy Grail.

The Glorious Twelfth, printed by the online Canadian publishing house Muse It Up, follows sacked archaeologist Ben Harris in his quest to find the ultimate treasure in Caithness.

Alan, who wrote his first book The Stuart Agenda in 2011, says: “There are plenty of twists in The Glorious Twelfth, mainly in the surprising behaviour of the characters, rather than Dan Brown type puzzles.

“It is similar to The Stuart Agenda in being a suspense mystery with its roots in history but has a stronger sense of place set in Caithness and European locations which I know well. Many of the locations are actual historic sites that helped to inspire the story.

“I found the second book easier to write than the first. Digital publishing does provide a learning curve for the new writer and, in fact, I’ve just finished writing my third novel and will be looking to publish this year.”

Born in Caithness, Alan, 68, moved to Wooldale in 1977 to work for ICI at Leeds Road.

He became one of the industry’s leading researchers and was awarded a CBE in 1996 for services to the chemical industry.

In his retirement he was appointed to the governors’ board at Huddersfield University.

It was a creative writing class at Holmfirth Adult Education Centre which spurred Alan into becoming a writer.

The Glorious Twelfth is available from or